The present invention relates generally to fluid delivery devices. More particularly, the invention concerns an improved apparatus, including a fluid dispenser having visual flow indicator means, for infusing medicinal agents into an ambulatory patient at specific rates over extended periods of time and a novel reservoir fill assembly for controllably filling the reservoir of the fluid dispenser, including a fill assembly for filling the reservoir in the field.
Many medicinal agents require an intravenous route for administration thus bypassing the digestive system and precluding degradation by the catalytic enzymes in the digestive tract and the liver. The use of more potent medications at elevated concentrations has also increased the need for accuracy in controlling the delivery of such drugs. The delivery device, while not an active pharmacologic agent, may enhance the activity of the drug by mediating its therapeutic effectiveness. Certain classes of new pharmacologic agents possess a very narrow range of therapeutic effectiveness, for instance, too small a dose results in no effect, while too great a dose results in toxic reaction.
In the past, prolonged infusion of fluids has generally been accomplished using gravity flow methods, which typically involve the use of intravenous administration sets and the familiar bottle suspended above the patient. Such methods are cumbersome, imprecise and require bed confinement of the patient. Periodic monitoring of the apparatus by the nurse or doctor is required to detect malfunctions of the infusion apparatus.
Devices from which liquid is expelled from a relatively thick-walled bladder by internal stresses within the distended bladder are well known in the prior art. Such bladder, or xe2x80x9cballoonxe2x80x9d type, devices are described in U.S. Pat. No. 3,469,578, issued to Bierman and in U.S. Pat. No. 4,318,400, issued to Perry. The devices of the aforementioned patents also disclose the use of fluid flow restrictors external of the bladder for regulating the rate of fluid flow from the bladder.
The prior art bladder type infusion devices are not without drawbacks. Generally, because of the very nature of bladder or xe2x80x9cballoonxe2x80x9d configuration, the devices are unwieldy and are difficult and expensive to manufacture and use. Further, the devices are somewhat unreliable and their fluid discharge rates are frequently imprecise.
The apparatus of the present invention overcomes many of the drawbacks of the prior art by eliminating the bladder and making use of recently developed elastomeric films and similar materials, which, in cooperation with a base define a fluid chamber that contains the fluid which is to be dispensed. The elastomeric film membrane controllably forces fluid within the chamber into fluid flow channels provided in the base.
The elastomeric film materials used in the apparatus of the present invention, as well as various alternate constructions of the apparatus, are described in detail in U.S. Pat. No. 5,205,820 issued to one of the present inventors. Therefore, U.S. Pat. No. 5,205,820 is hereby incorporated by reference in its entirety as though fully set forth herein. U.S. Pat. No. 5,721,382, also issued to one of the present inventors, describes various alternate constructions and modified physical embodiments of the invention, including the provision of a novel fluid actuated indicator means for visually indicating fluid flow from the device. This latter U.S. Pat. No. 5,721,382 is also hereby incorporated by reference in its entirety as though fully set forth herein.
Another somewhat similar apparatus to that of the present invention is described in application Ser. No. 09/250,036 filed by the present inventors on Feb. 12, 1999. Because of the pertinence of this application, U.S. Ser. No. 09/250,036, now U.S. Pat. No. 6,086,561, is hereby incorporated by reference as through fully set forth herein.
The apparatus of the present invention can be used with minimal professional assistance in an alternate health care environment, such as the home. By way of example, devices of the invention can be comfortably and conveniently removably affixed to the patient""s clothing or to the patient""s body and can be used for the continuous infusion of antibiotics, hormones, steroids, blood clotting agents, analgesics including morphine, and like medicinal agents. Similarly, the devices can be used for I-V chemotherapy and can accurately deliver fluids to the patient in precisely the correct quantities and at extended microfusion rates over time.
One form of the apparatus of the present invention uniquely permits the reservoir of the fluid-dispensing component to be filled in the field.
Another form of the apparatus of the invention includes novel volume control means for precisely controlling the volume of fluid to be introduced into the reservoir of the dispensing component.
It is an object of the present invention to provide an apparatus for delivering fluids at a precisely controlled rate which comprises a fluid dispensing component having a fluid reservoir for containing the fluids to be delivered and a reservoir fill component which can be removably interconnected with the fluid dispensing component. More particularly, it is an object of the invention to provide such an apparatus in which the reservoir fill component can be used in the field to controllably fill the reservoir of the dispensing component and in which the dispensing component can be used for the precise infusion of pharmaceutical fluids to an ambulatory patient at controlled rates.
It is another object of the invention to provide an apparatus of the aforementioned character which is highly reliable and easy-to-use by lay persons in a non-hospital environment.
A further object of the invention is to provide an accurate and highly reliable fluid delivery device which can be manufactured inexpensively in large volume by automated machinery.
Another object of the invention is to provide an apparatus of the type described in the preceding paragraphs which includes novel volume control means for precisely controlling the volume of medicinal fluids that are introduced into the reservoir of the fluid dispensing component.
Another object of the invention is to provide an apparatus of the character described that includes first and second reservoir fill assemblies for filling the fluid reservoir of the fluid dispensing component.
Another object of the invention is to provide an apparatus of the aforementioned character which includes a delivery component and a filling component which can be operably interconnected with the delivery component to enable expeditious filling in the field of the reservoir of the delivery component. More particularly, the first fill assembly permits the pharmacist to aseptically fill the container under patient-specific-variable volume and concentration of medicament. In this way, body mass index requirements can be met for selected agents as, for example, immuno- and-chemo-therapeutic agents.
Another object of the invention is to provide a device of the class described in the preceding paragraphs in which the dispenser component embodies a highly novel fluid flow indicator that provides a readily discernible visual indication of fluid flow status through the device.
Another object of the invention is to provide a device of the aforementioned character in which the dispenser component includes a novel infusion means in the form of delivery line assembly, which can be interconnected with the dispenser.
Another object of the present invention is to provide a second reservoir fill means in which the container of the fill means is partially received within a novel adapter subassembly that can be sealably connected to an outlet port provided in the base of the fluid dispensing device.
Another object of the invention is to provide first and second reservoir fill assemblies for use with the fluid dispenser subassembly of the apparatus which are easy to use, are inexpensive to manufacture, and which maintain the container of the fill assemblies in a substantially aseptic condition until time of use.
Other objects of the invention are set forth in U.S. Pat. Nos. 5,205,820 and 5,721,382 and 6,086,561 all of which are incorporated herein by reference. Still further objects will become more apparent from the discussion that follows.
By way of summary, the fluid delivery apparatus of the present form of the invention comprises four cooperating components, namely a fluid delivery apparatus or dispenser, an infusion means for infusing medicaments into the patient and first and second reservoir fill assemblies which can be coupled with the fluid dispenser component for filling the fluid reservoir thereof. The fluid dispenser, which readily lends itself to automated manufacture, is generally similar to that described in U.S. Pat. No. 5,721,382 and includes a base and a stored energy means comprising at least one distendable elastomeric membrane which cooperates with the base to form a fluid reservoir. The fluid dispenser includes a highly novel fluid flow indicator means which is substantially similar to that described in U.S. Pat. No. 6,086,561 and comprises a mechanical fluid flow indicator that provides a clear visual indication of normal fluid flow and absence of fluid flow from the fluid reservoir. One form of the reservoir fill means of the invention also uniquely includes volume control means for controlling the volume of fluid to be introduced into the reservoir of the fluid dispenser by one of the fill means of the invention.